Surface and undersea craft as well as shore installations using heavy duty machinery have a complicated network of heavy duty pipes and fittings. It is common to join successive links of pipe and elbows etc. by bolts extending through pipe boss flanges of successive sections. Since liquids and gases are fed through the piping sections the interconnections must be sealed and properly aligned. During the fabrication of new interconnections and the refurbishment of existing connections the holes through which the bolts extend must be properly aligned. Usually this calls for providing elaborate support guides or make shift rigs to guide a standard portable power drill. Particularly, with large surface and undersea craft staging having heavy duty platforms usually need be erected to provide a mounting surface for the support guides and makeshift rigs. The time, materials and other cost factors incurred while erecting the staging and other supportative measures often far exceed the actual work requirements. Heretofore, such expenses were an unavoidable burden that had to be borne when massive pipe boss flanges were located at critical elevations or at precarious locations. There is a continuing need in the state-of-the-art, therefore, for a machine which will drill and tap new and refurbish existing tapped and untapped pipe flange bolt holes which is self-aligning and which doesn't require time consuming and costly supporting structures.